Hardtop00SS

iTrader: (17)

I just got my Chevy High Performance in today and there was an article titled "7 1/2 is enough" that talks about the 7.5 rears in 3rd & 4th gen F-bodies saying that it will hold up to 400 ponies at the wheels with the right parts! Even Moser backed them up saying that the 7.5 is adequate for the street/occasional strip car. The rear they were building was for the CHP IROC project car (Auto). They put in Moser 28 spline axles (claim they're 20-25% stronger then factory axles), Moser gears (3.42), Auburn LSD, and TA Girdle. Moser claimed in the article, that if you are over 400 HP and go to the strip quite often, that a 12 bolt or 9" is needed, but other then that, they RECOMMEND to their customers that the 7.5 will work for them. Just thought I'd share this with other people and get some feedback on what people think about this article.

Robbie

SPANKY LS1

iTrader: (24)

7.5" axles = $300
Moser gears = $180
Auburn LSD = $450
TA Girdle = $150
Labor = $150

Still having a POS rearend, and having spent over half the cost of a 12 bolt or 9" = PRICELESS



Seriously, you can put all of the makeup in the world on a pig, but its still a pig. The stock rearend has proven itself to be a inferior piece, I would not waste a dime on it if you intend to race, period. Just my .02, Shawn

LS1NOVA

iTrader: (12)

Why beat around the bush, Just do it right the first time and you wont regret it.
7.5=boat ancor if you are going to run the car hard.

The Big Show

iTrader: (2)

You also have to look at what commonly breaks on these rears and its not the axles. I'm surprised Moser hung themselves out like that in the article when its pretty common knowledge that these rears (especially in 6 speed cars) can hardly stand up to stock hp.

Jorday

I wouldn't toss too much money into the stock rear.

KGSloan

like said, tossing money at the stock rear is pretty pointless. you still have a really small weak posi unit, and that tiny ring gear. it won't last long. i really like what spanky wrote, i think he's right on

2001 Pewter WS6

iTrader: (43)

They'll hold up fine in an A4. They won't last in a 6 speed car because of the shock the rear gets when you dump the clutch. Like taking a decent size stick and setting it on your knee. Push on it and try to break it. Now take that same stick hold it 18" above your knee and slam it down. It will snap a lot easier. With an A4 the rear gets preloaded when you are on the gas and brake at the same time. No doubt a 12 bolt is stronger but a modified 6 speed can tear apart one of those as well..

Gary Z

The durability of the stock rear is highly dependent on the tires you run. With 16-nch GSC Eagles it can survive many 4000 rpm clutch dumps. If you use big sticky tires you'll break it with stock HP.

mcflyz28

Put DR's on twice she be whining like a B***, it's crap period end of discussion.

Ragtop 99

iTrader: (7)

Seen A4's break the axles on a stock rear too.

For pure street use as a daily driver and occasional stoplight racing, the stock rear may hold up ok.

For track use with ET streets, make sure your AAA membership is paid up first.

jimmyblue

iTrader: (11)

It's "enough" for people who think an SLP MAF is a major
performance upgrade....

Speedfreaks101

Two things to think about

1. I would bet that the magazine would take things out of context and misconstrue something to make thier "build-up" look more appealing to the reader. Moser probably said something like "It might make it a pass or two down the track" and then the magazine totally fabricated the rest of the quote. Do you think that Moser is going to try and knock themselves out of a sale of a 2500 dollar rear end?

2. If the LS1 guys are having problems with the 12 bolts holding up under power then why in the hell would a 7.5 inch 10 bolt hold up?????

Later,
Bart

Hardtop00SS

iTrader: (17)

lol, yea I thought it was kinda weird that Moser said "We actually tell our customers that the 7.5 will work for them in certain application". All I know is that that article didn't sell me, I still think that the 7.5 is indeed garbage. Somebody on this website summed it up just right with this line, "beefing up the 7.5 rear is like putting a bandaid on a gunshot wound, it's not going to help it"

Robbie

42NightZ28

A Stock rear is fine if your running street tires (not DRs) I wanted Slicks and i wanted to run a taller gear, so i just saved up and got the 9in. PS if you have a 2.73 geared car with the Steel DS swap that SOB out with a 3.5in Aluminum one. the Weight diff is nuts.

SScam68

iTrader: (20)

lmao, that is so true

BADSZ28

iTrader: (39)

My 10 is halfway done. I bent an axle and swapped in some moser's with a T/A girdle with only 10k on the car. Didn't have the money for a 12. Now I want gears. My rear is fine after 20k even with 5k of those on nittos. I hit the track about 3 times a year. I drive pretty hard. I think I may just finish it off with a gear and possi. Should hold up for a couple years. I have heard of guys running tens on them. By then I can afford a 12.

P.S. Yes sh**ty axles can mess up the hole rear. The stock ones flex under load, good axles don't. With less flex there is less chance of blowing the rear.

SSZSLP

Less flex would then equal more stress on the ring and pinion,then more chance of "blowing" rear

BADSZ28

iTrader: (39)

Sure, for a factory ring and pinion. I'm talking about installing Motive or Richmond gears. Much stronger. Regardless of the gear, flex causes miss matched mesh in the gears, that is why they go. Most rears that go have broken teath in the gear. Even when there is a strong aftermarket gear. If you blow a gear and not the diff., you have too much flex (especially when aftermarket gears are installed). Stronger axles with girdle and good gear and diff. will hold fine in a 10.

Fast SS on TNT

iTrader: (1)

Thats all I have to say about the 10 bolt rearend. CHP may be under pressure from sponsors that want to sell you band aids for a 10 bolt, when in all actuality you need major surgery.

I have seen 4 cars shred the 10 bolts with drag radials and either a strong clutch or an A4 and converter. I broke my 10 bolt when I hit a bump while doing a little street run. I still think GM should have a little box to check when you order a car for a PERFORMANCE 12 BOLT REAREND. I would of paid any reasonable amount for that option.

hawaiiboysz

iTrader: (4)

I concur! I would have checked that box